I like Rufus and Jethro together, but Goku sticks out like a sore thumb. I've never watched Dragon Ball, so i have never heard of Goku, but it reminds me of Roku, which is an electronics company.

Goku seems to me to have a very different 'vibe' than Rufus and Jethro. Milo seems like it would fit better in its place, but i dislike that it shares Jethro's o-ending. Do you like any of the following: Digby, Fergus, Abram, Felix, Basil (both pronunciations)? Those seem to 'fit' better with the sound and feel of Rufus and Jethro, imo.